Add an ifdef around the use of google::GLOG_WARNING

MSVC requires using google::GLOG_WARNING, but this breaks the build
inside google. So add a MSVC specific ifdef to guard against it.

Change-Id: I3509bb3fd2c01722a1c76545b57d2bf0224f6d6e

internal/ceres/levenberg_marquardt_strategy_test.cc

@@ -145,10 +145,19 @@ TEST(LevenbergMarquardtStrategy, CorrectDiagonalToLinearSolver) {
   {
     ScopedMockLog log;
     EXPECT_CALL(log, Log(_, _, _)).Times(AnyNumber());
+    // This using directive is needed get around the fact that there
+    // are versions of glog which are not in the google namespace.
+    using namespace google;
+
+#if defined(_MSC_VER)
     // Use GLOG_WARNING to support MSVC if GLOG_NO_ABBREVIATED_SEVERITIES
     // is defined.
-    EXPECT_CALL(log, Log(google::GLOG_WARNING, _,
+    EXPECT_CALL(log, Log(GLOG_WARNING, _,
+                         HasSubstr("Failed to compute a step")));
+#else
+    EXPECT_CALL(log, Log(WARNING, _,
                          HasSubstr("Failed to compute a step")));
+#endif
 
     TrustRegionStrategy::Summary summary =
         lms.ComputeStep(pso, &dsm, &residual, x);